Sprocket-wheel.



W. HAY.

SPROCKET WHEEL,

APPLICATION r1150 AUG-H- 191a.

jl fi fiu Patented Apr. 17, 1917.

fee

WALTER HAY, 0F SEVILLE, OHIO.

SPBQCKET-WHEEL.

Application filed August 11, 1913.

To all whom it may concern Be it known that I, WALTER HAY, a citizen ofthe United States, residing at Seville, in the county of Medina andState of Ohio, have invented new and useful Tmprovements inSprocket-Wheels, of which the following is a specification.

This invention relates to sprocket-wheels in which the teeth are formedindependently of the body portion.

The principal objects are to provide a sprocket-wheel constructedlargely of sheet metal and in which the accuracy of milled teeth iscombined with the cheapness of punch-press products; in which eachseparate tooth is formed with a section of the wheel rim, thus enablingthe teeth and the rim to be heat treated and then assembled absolutelytrue to pitch; in which the teeth are firmly, yet removably secured tothe body in such manner as to prevent them from becoming loose,regardless of the length or severity of service; and in which the huband the method of securing same to the body portion or web conform tothe other parts of the wheel in simplicity, cheapness and dependability.

I am aware of the fact that toothed wheels have been devised. heretoforein which the teeth were formed from a continuous strip of sheet metaland then secured to the rim or body portion; also that sheet metal teethhave been formed separately and then secured into the body portion.However, with the former construction, hardening of the teeth in stripswould destroy the accuracy of the pitch, and a broken tooth could hardlybe replaced without renewing the entire strip of teeth. With the latterconstruction, in all cases known to me, each tooth requires two separatefastening means, and where the body portion is solid and suflicientlythick to accommodate wide teeth or wide chains, the cost of material andmachine work would show no economy over a solid wheel with milled teeth;were the body portion more cheaply constructed with two sheet metaldisks, then objectionable openings would appear between the teeth, andthe rim bearing-surfaces for achain would be.

inadequate; and were it desired to harden the rim, the accuracy of thepitch would be destroyed during heat treatment.

It is believed that the foregoing brief thesis on other wheels havingsheet metal teeth, when considered in connection with Specification ofLetters Patent.

Patented Apr. 1?, 1915?. Serial No. 784,160.

the followin detailed description, will enable a clearer understandingof the features of improvement comprised in my invention.

quently presenting the appearance of a sheave. Equally spaced around theouter edge of the body disks are oppositely dis posed circular openings12 (see also Fig. 3), with slots 12 extending therefrom and through therim. The tooth 13 (see also F td and the rim section 13 are constructedof one piece of sheet steel, the ends of which project inwardly throughthe slots 12. and have a semi-circular form 13 and 18 to correspond withthe openings 12. In assembling, two or more teeth with their integralrim sections are entered into the body portion from the side, the rimsections fitting closely the periphery of the body-disks, and thesemi-circular end of a rim section and the semi-circular end of anadjoining tooth are brought together in each of the openings 12, thusforming practically a series of tubes in halves, into each of whichtubes thus made is forced around pin 14 which causes expansion of thetubes and thereby the teeth and rim sections to be firmly and dependablysecured to the bodydisks.

From a study of Fig. 1 it is obvious that the openings 12 and slots 12can be made true to pitch and at low cost in a punchpress by aid of anindexing device, and if the wheels were to be made in large quantities,all the openings and slots could more cheaply be punched in oneoperation; also that there being no wear on the rims of the body-disks,hardening of same is unnecessary and consequently the diameter of sameand the pitch of the slots always remains true; also that the width ofthe slots, which are preferably made radial, is only twice the thicknessof the sheet steel used for the teethrim sections, hence the latter arerigidly secured against lost motion and mutually braced to withstand thepull of a chain. Each tooth with its respective rim section being aunit, hardening of same causes but slight change in its form; however,all Shrinkage or distortion resulting from heat treatment is rectifiedin assembling, the radial slots in the body-disks bringing each toothtrue to pitch. By removing two pins any broken or injured tooth-rimsection may easily be replaced; and similarly, when considerably worn,all the teeth can be replaced with new, the body, disks, due to theprotection afforded by the rim sections, retaining their originaldiameter and so helping to maintain the original pitch-diameter of thechain when the teeth-rim sections are renewed, or possibly reversed.Further, it will be observed that, for the purpose of securing theteeth-rim sections to the bodydisks, there are only as many fasteningmeans as there are teeth, which method promotes economy in several ways.

In order to extend, primarily, cheapness of construction, and, alongtherewith, rigidity and exactness to every detail of my newsprocket-wheel, I have adopted the hub construction shown in section inFig. 2. The hub 15 is preferably made of steel, somewhat higher incarbon than the body-disks, and around the outside circumferentially isturned an oval-shaped raised portion 15 which is then knurled, theresulting teeth running lengthwise of the hub. The bodydisks areassembled on the hub, one on each s1de of the ralsed portlon, and thewhole placed in a powerful press which, with the aid of a guide stud tosquare the hub and the proper gaging arrangement, forces the twobodydisks together and over the knurled raised portion (the teethcutting into the softer metal of the body-disks). The body-disks arethen riveted together, thus rigidly securing the hub thereto, the teethmade by knurling-preventing movement of the body-diskscircumferentially, and the oval shape of the raised Copies of thispatent portion preventing movement of same laterally, both relatively tothe hub.

What I claim as my invention is 1. In a sprocket wheel, the combinationof a body comprising disks, each of said disks having a hub opening,having a curved portion to provide an annular channel when the disks arein engagement with each other, a plurality of independent toothsections, each tooth section having ends extending toward the hubopening, each end having a curved portion whereby when the adjacent endsof the tooth sections are brought together, the curved portions formcircular portions, a pin extending through each of the annular channelbetween the disks and through circular portions for holding the teethbetween the disks, and means for securing the disks together adjacentthe hub openings.

2. In a sprocket wheel, the combination of a body, a plurality ofindependent tooth sections formed with chain-supporting extensions, eachtooth section having its ends extended into the body, each end having acurved portion whereby when the adjacent ends of the tooth sections arebrought together, the curved portions form circular or tubular portions,and. a pin extending through each of the circular portions for securingthe tooth sections to the body.

3. In a sprocket wheel, the combination of a body, a plurality ofindependent tooth sections, each tooth section having its ends extendedinto the body, each end having a bent portion whereby when the adjacentends of the tooth sections are brought together, the bent portions formtubular portions, and means cooperating with the tubular portions forsecuring the tooth sections to the body.

WALTER HAY.

Witnesses i H. E. KRAMER, W. G. BRUMBAUGI-I.

may be obtained. for five cents each, by addressing the Commissioner ofPatents,

Washington, D. G.

and each disk

